// <editor-fold defaultstate="collapsed" desc="GNU GPLv3 Header">
/*
 * File:   AlawEncoder.c
 *
 * Copyright (C) 2013 Robert Antoni Buj Gelonch <rbuj@uoc.edu>
 * Copyright (C) 2013 David Megias Jimenez <dmegias@uoc.edu>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
// </editor-fold>

#include "../AlawEncoder.h"

void AlawEncode(short int* sample, char* compressed) {
    int aux = abs(*sample);
    if (aux > 0x0FFF) {
        fprintf(stderr, "Only 13-bit signed\n");
        exit(EXIT_FAILURE);
    }
    char exponent = aLawCompressTable[(aux >> 5) & 0x7F];
    char mantissa;
    if (exponent == 0) {
        mantissa = (aux >> (exponent + 1)) & 0x0F;
    } else {
        mantissa = (aux >> (exponent)) & 0x0F;
    }
    (*compressed) = ((exponent << 4) | mantissa) & 0x7F;
    if ((*sample) < 0) {
        (*compressed) = 0x80 | (*compressed);
    }
}

void AlawEncodeTransmission(short int* sample, char* compressed) {
    AlawEncode(sample, compressed);
    (*compressed) = (*compressed) ^ 0x55;
}
